Grinding or crushing mill



J. R. TORRANCE GRINDING OR CRUSHING MILL {Med Feb. 25, 1922 2 Sheets-Sheet 1 J. RTORRANCE GRINDIFJG 0R CRUSHING MILL Jan. 20, 1925- Filed Feb. 35, lggg 2 Shuts-Sheet 2 INVENTOR IIL Jbhn Paw 70rmnce Patented Jan. 29, 1925.

UNITED STATES JOHN ROXVLAND TORRANCE, OF BITTON, ENGLAND.

GRINDING OR CRUSHING MILL.

Application filed February 25, 1922.

7'0 (:23 ic/iom it may coomm'vtx Be it known that I, J OHN ROWLAND Ton- RANCH, a subject of the King of Great Britain, residing at Bitten, England, have invented certain new and useful Improve ments in and Relating to Grinding or Crushing Mills, of which the following is a specification.

The present invention relates to improvements in and relating to grinding or crushing mills and particularly in such mills to improved means for transmitting a drive from one rotating member to another, the members being eccentrically disposed.

The present invention will be hereinafter described in relation to disc and the like grinding mills, particularly those, whether suited or adapted to dry grinding or to grinding fluids or mixtures which become fluid after grinding, of the kind consisting of an. upper perforate grinding organ which forms a receptacle for the material to be ground and the lower face of which forms a grinding surface; the other grinding surface being a rotating disc which bears against the grinding surface of the receptacle, and in which the grinding members are two flat discs of stone, porcelain, metal or like, and the grindin members while held in the required proximity with each other grind one over the other with a compound relative rotary and lateral bodily movement.

In the hereinafter described embodiments of mills of this kind. the compound rotary and lateral bodily movement of the running stone is imparted in known manner either by means of a crank or eccentric pin on which rotates a driving sleeve connected to the grinding disc, on the one hand, or by means of ashaft eccentrically mounted free to rotate in a rotatable sleeve, on the other hand.

In either of the above mentioned types of mills the ditliculty presented is to impart drive of rotation to the sleeve on the crank or eccentric pin, or to the shaft in the eccentric sleeve, from an eccentrically disposed member.

The usual drives by internal ring and pinion gear, and mechanisms of the horn or prong type, are open to the objection of keeping in step with the eccentric cycle changing as they do in phase with the eccentric cycle, and constantly maintaining the thrust at the same point, setting up severe heat, which causes seizures and breakages Serial No. 539,260.

and militates against fine grinding, so much so, that it becomes impossibleor very difiicult to produce a mill of the dimensions suited for serious work, i. e., a profitable output of a high quality product.

Now an object of the present invention is to overcome the above disadvantage by realising a. balanced drive of rotation of the running stone from a member eccentrically disposed with respect thereto through the medi ation of a third member which rotates concentrically with respect to the running stone and is so coupled that the point of drive is constantly maintained to move out of phase with the eccentric cycle, the medial member being connected to exert or react to torque which is balanced or equal on opposite points of the axis.

The medial member being concentric with the running stone is eccentric to the member to which it is connected. to receive drive, and for the point of drive to be constantly main tained and to move out of phase with the eccentric cycle, a single pin and slot connection, or a connection of this character serves. In the hereinafter described example in which the medial member is a sleeve which is driven from a gear eccentrically mounted with respect to the sleeve, a single lug on the gear engages a. radial slot in the sleeve, the slot being formed so as to accommodate the lug at any position in its eccentric path with respect to the slot.

The present invention may be convenient ly and advantageously carried into effect as hereinafter appears, reference being had to the accompanying drawings, in which Fig. 1 shows a sectional elevation of the mill.

Fig. 2 a part sectional plan on the line 2-2 (Fig. l) of worm wheel bracket. wornr shaft, worm and spur wheel. I

Fig. a part sectional plan. on the line 3--3 (Pig. 1) of the trough showing front scraper and bottom disc.

Fig. '-.'t a part sectional plan on the line 44 (Fig. 1) showing the sweeper and operating gear as described below.

Figs. 5 and 6 are enlar ed sectional elevation and plan of the drive as applied to a crank or eccentric pin type of mill, F ig. 6 being taken substantially on the line 6-43 (Fig. 5)

Figs. 7 and 8 are enlarged sectional elevation and plan of the drive as applied to an eccentric shaft type of mill, Fig. 8

Ill)

being taken substantially on the line 88 g Fig. 9 is a part sectional plan of the drive applied to operate a scraper to sweep out the trough.

Fig. 10 is a part sectional elevation taken on the line 1010 of Fig. 11.

Fig. 11 is a plan view of the driving head.

In application to-the aforesaid crank or eccentric pin type of mill, and referring to Figs. 1 to 6, the medial drive sleeve 64 is rotatably mounted on crank or eccentric pin?) on the upper end ofthe mill shaft 0. the upper end of the sleeve is provided asa spigot end with a ballhead or top (Z to receive the lower grinding member 9 to which it transmits motion through a cross pin it fixed in thespigot, the pin 72, engaging with slots diametrically opposite in the boss 0 of the retaining dish of-the lower grinding member g." The slots are given surficient depth to allow the stone to swivel on the ball head (Z.

i is the upper stone which may be water cooled.

The drive of the sleeve a is effected by pin or lug j and relieved slot connection is between a boss [of a gear m rotatably mounted on the outside of-the shaft bearing, and the sleeve, the slot preferably being radially disposedin a ring-like expansion 0.

of the lower end of the sleeve a andbeing appropriately relieved to accommodate the eccentric relationship of the connected membe-rs, a and m, respectively.

In a constructional form of paint or like mill as illustrated, the main vertical bearing is formedin the long boss 39 of a bracket 1' bolted between side memberss of the mill frame, and in this long boss p the vertical shaft 0 revolves at the speed of-the orbital motion, transmitted through worm gearing t, '0. The crown bevel wheel m positioned by a collar revolves about a liner 71. secured] by set pins 07. 1

On the eccentric part I), of. the shaft 0 the driving head or sleeve a fits, but freeto revolve at the same speed as the bevel wheelm the slot 7c in the bottom of the driving head a engaging the tooth 011 the bevelwheel m. Interposed between the shaft 0 and the dr ving head a 1s a bronze llner y which is, free to revolve on the s'haft o, or in the bore of the driving head d.

The grinding thrust between the head or sleeve (0 and the shaft 0 is taken by a ball thrust bearing Z fitted in the head or sleeve 'a.

Referring to Fig. 4a pinion or star wheel- 2, having four teeth for example, may be rotatably" mounted-uponthe neck of th e A bevel pinion 9 fast on amain driving shaft 10 drives the bevel wheel m; Mounted on'the neck ofthedriver gear 9 to rotate. therewith is a spur wheel 11 which drives a spur wheel 12 on the shaft 15 for. driving the. worm gearing t and v. I

The shaft 0' is free to slide. through the bore of the worm wheel 1), the drive to the shaft being obtained by means ofafeather... In operation, the. shaft 0 isrevolved slow-.

ly in its bearing by the worm gearing. t, o, and the top part b of the. shaft beingturned eccentric to the portion in the bearing moves in an orbit round the common centre linev of: the shaft, and mill. eccentric top portion 6 of the shaft 0 is the head; or sleeve a free to rotate thereon, this head is driven by the bevel'wheel m through the tooth .j and slotlc, which allows the necessarysliding movement due to the wheelm and head or sleeve a being. eccentrically dis posed, tliebeve]. wheelm and head arunning. at a speed. which is high. in relation to that of. the; shaft.

With thediscs havingv an everqvarying. cross or lateralin addition to the. circu? larmotion, the grinding. surfacesdo not deteriorate, but retain theirtrne form indefinitely, and re-dressing. or. truing up.

periodically is but little if at all required.

' 16.and .17 'indicate an oil feed' delivery for.

with the bore whichfreceives the. shaft; 20.

that it is desired to drive with, abalanced torque or turning effort. Otherwise the ec-, centric sleeve is formed.e'Xteriorlyv eccentric tothe bore.

Mounted upon the On the" eccentrlc sleeve 19 immediately.

above the exterior concentric portion there: of. is rotatably mounted a gear, for .ex'anr ple, a bevel gear 21'which is suitablydri'ven, and under this gear and on the exterior concentric portion 18 of the eccentric sleeve 19 is rotatably. inounted a drive sleeve 22 which is driven from the gear bya lug or pin andlslot23, 2 1, the slot 24; preferably being formed in a ring-like expansion at the upper end of the sleeve, and being relieved for accommodating the varying positions assumed by the lug or pin 23 on the boss of the gear 21 by virtue of the eccentric relationship of the connected members, the relative sliding motion of the lug and slot realizing the transmission of a free and smooth motion from the gear 21 to the sleeve 22.

The drive sleeve 22 and the shaft 20 which is eccentrically mounted in the rotatable sleeve 19 and projects beyond it at the lower end can now be so coupled together as to ensure that the torque or turning effort shall be equal at opposite points of the shaft and the thrust on the shaft bearings reduced to a minimum.

A simple connexion for this purpose comprises a pair of slots 25 diametrically opposite in a ring-like expansion 26 of the lower end of the medial drive sleeve 22, and corresponding pins 27 on the shaft 20 to engage the slots 25. Other balanced connections are obviously available.

The eccentric sleeve 19 is rotatably mounted in a main neck bearing 28 forming a fixed part of the casing of the grinding members and is driven by a worm wheel 29 fast on the sleeve 19.

Drive is imparted to the worm wheel 29 and the bevel gear 21 in a similar manner as that hereinbefore described with reference to the eccentric pin type of mill.

By changing the gearing such as 11, 12, the velocity ratio up and down between the rotatory drive and the lateral bodily drive may be varied as desired.

In both examples of mill hereinabove given the drive is freely and smoothly transmitted through the medial member a or 22 to the running stone 9, and thrust and wear is distributed evenly over the bearing surfaces as the point of drive is constantly moving forward and out of step with the eccentric cycle and the drive to the running stone is balanced for all practical purposes, the torque being equally divided on opposite sides and consequently the thrusts are opposite and opposing. Consequently the mill runs remarkably cool under all working conditions, and the grinding is notably fine, consistent, and profitable.

-What I claim is:

1. The combination in a grinding mill of the kind described, of co-operating flat grinding members, means for imparting to one of said grinding members an orbital movement, abaXial members for imparting a drive of rotation to said orbital moving grinding member at the same time as the orbital movement, and a single pin and slot driving coupling connecting the abaXial members such that the angular point of drive between the said abaxial members remains unchanged and moves out of phase with the orbital movement of the said grinding member.

2. A grinding mill of the kind described comprising co-operating fiat grinding members, a shaft bearing, a shaft rotatably mounted therein, an eccentrically disposed upper portion on said shaft, a sleeve rotatably mounted on the eccentrically disposed upper portion, a connection between said sleeve and one of the grinding members for imparting a rotatory drive thereto, means for rotating the shaft, means for rotating the sleeve comprising a driving member concentrically disposed with respect to the shaft and a driving coupling connecting said driving member and said sleeve whereby the angular point of drive between the driving member and the sleeve remains unchanged and moves out of phase with the orbital move ment of the sleeve, substantially as described.

3. The combination with a grinding mill as claimed in claim 2 hereof of a trough scraper and means for driving the scraper in a reverse direct-ion to the orbital move ment of the running grinding member substantially as described.

4. The combination with a grinding mill as claimed in claim 2 hereof of an edgescraper and means for yieldingly urging said scraper against the running grinding member, substantially as described.

5. A grinding mill of the kind described comp-rising co-operating fiat grinding members, a shaft bearing, a shaft rotatably mounted therein, an eccentrically disposed upper portion on said shaft, a sleeve rotatably mounted on the eccentrically disposed upper portion, a connection between said sleeve and one of the grinding members for imparting a rotatory drive thereto, a common main driving shaft, means for rotating the sleeve, and means comprising intermediate worm gearing for rotating the shaft substantially as described.

6. The combination with a grinding mill as claimed in claim 5 hereof of a trough scraper and means for driving the scraper in a reverse direction to the orbital movement, substantially as described.

7. The combination with a grinding mill as claimed in claim 5 hereof of an edgescraper and means for yieldingly urging said scraper against the running grinding member, substantially as described.

8. A grinding mill of the kind described comprising co-operating flat grinding members, a shaft bearing, a mill shaft rotatably mounted therein, an eccentrieally disposed upper portion on said shaft, a sleeve rotatably mounted on the eccentrically disposed upper portion, a connection between said sleeve and one of the grinding members for imparting a rotatory drive thereto, a common main driving shaft, means for rotating the sleeve, a counter shaft, means comprising worm gearing carried by said counter shaft for rotating the mill shaft, and gearing intro'duce'd between the main shaft and the counter'shaft for the purpose set forth.

9. A -grinding mill of the kind described comprising co-operating flat grinding. members, a shaft bearing, a shaft rotatably mounted therein, an eccentrically dis-posed upper portion on said shaft, a slee-ve rotatably mounted on the ecc entrically disposed upper portion, a connection between said sleeve and'one of the' gr-inding members for imparting a rotatory drive thereto, a common main driving shaft,:means*for rotating the sleeve comprising a bevel; gear the driven bevelbeing rotatably mounted on. theshaft --bearing, a radially moving coupling connectingthe said driven beveland the said sleeveyand means for rotating the shaft comprising Worm gearing, substantially as described.

10. A grinding mill of the .kind described comprising co-operating flat grinding mem bers, a shaft bearing, amill shaft rotatably mounted therein, an eccentrically =disp sed upper portion on saidshaft, a sleeve'rotatably mounted on-"the eccentrically. disposed vbearing, a radially moving coupling connecting the said driven bevel, and the said sleeve, a counter shaft, means compris ng Worm gearing 'CZlIfIflGd by said counter shaft 'for rotating the mill shaftfaiidfgearing ino I grinding members, abaxial members for 1mparting, a drlve of rotation through abaXlal members,lmeans 'for imparting the orbital -moveinent, means for imparting 'lthe rotatory movement and a radialmovable singlepin and slot coupling connecting the sa-id abaxial members for the purpose 'd scr'ibe d.

12. In agrinding-mill as claimed in claim 11 hereof the combinationof a trough scraper and means for driving said scraper in a reverse direction to the orbital movement of the running grinding member, substantially as described. e

13. In a, grinding mill'as claimed in claim 11 hereof the combinationof an edge-scraper and means for-yield -ingly urging said scraper against the runninggrinding member, substantially as described.

In testimony whereof, I affix my s'ig'nature.

JOHN ROWLAND T'o'RRANon. 

